.container() {
    .center-block;
    max-width: @container-gutter*2 + @cw;
}

.em(@target: @browser-context, @context: @browser-context ) {
    font-size: unit(@target /@context, em);
}
    
.rgba(@colour, @alpha)
{
    @alphaColour: hsla(hue(@colour), saturation(@colour), lightness(@colour), @alpha);
    @ieAlphaColour: argb(@alphaColour);
     
    background: @alphaColour; 
     
    .lt-ie9 &{
        background: transparent;
        -ms-filter:  "progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})"; 
    }
}

.ie-rgba(@colour, @alpha){
    
    @alphaColour: hsla(hue(@colour), saturation(@colour), lightness(@colour), @alpha);
    @ieAlphaColour: argb(@alphaColour);
     
    .lt-ie9 &{
        background: transparent;
        -ms-filter:  "progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})"; 
    }
}

.align(){
    position: absolute;
    left: 50%;
    .translate(-50%, 0);
}